1. Field of the Invention
This invention relates to hand knives having ring-like rotary cutting blades used primarily in the packing house and meat distribution industries.
2. Prior Art
Hand knives having power-driven, ring-like rotary blades have been used for some time in packing houses, meat distribution or wholesale houses and the like, for trimming and/or slicing meat and removing meat particles from bone. Such knives are commonly referred to as trimming and slicing knives and boning knives. Examples of such knives are shown in U.S. Pat. No. 3,852,882. The ring-like blades are typically supported in the blade housing by an external flange on the blade engaging in an interior groove-like aperture in the blade housing. The ring-like blades rotate in a sliding relationship within a ring-like housing. During use of the knife a portion of the blade opposite the handle is pressed against the product being processed and normally drawn in the direction of the operator causing portions of the blade remote from the handle to be drawn against the housing and in some instances the blade is distorted because of its relative thinness. The rubbing of the blade against the blade housing results in wear of the housing which is typically made of softer material than the blade with the result that the blade becomes unduly loose in the blade housing reducing the efficiency of the knife and ultimately loss of drive. Pressing the blade against the product being processed also tilts the blade in the blade housing which results in further wear between the blade and housing.
The concentration of wear between the blade and housing at specific locations around the housing as mentioned above results in premature weakening of the housing and creates excess clearance between the blade and housing, with an accompanying failure of the housing to maintain the blade in a position necessary for smooth running of the blade and proper engagement of the drive mechanism with the blade. Excess clearance between the blade and housing also makes it difficult to effectively hone or sharpen the blade without removing it from the housing. Replacement of the housing and blades necessitated by such excess wear can result in a substantial increase in the cost of using the knives, especially where large numbers of knives are used.